Snap-on securing clips for the lids of sheet metal containers



April 24, 1956 J. s. HAWKSWELL ET AL 2,743,128

SNAP-0N SECURING CLIPS FOR THE uns 0E SHEET METAL CONTAINERS Filed Oct. 20, 1952 @j @En ,United States Patent 0;

SNAP-N SECURINGCLIPSFOR THE LIDs oF n' 5 .lohn S. Hawkswell, Ambleside,Westmorland,y andf George FrPorter, Ilford, England, assignors to The Self- Opening Tin Box Co. Ltd.,.Barking,y England, a Bl'itislrcom,u ,panyl v t Application october 2o, 1.9'52, serial Nm3-15,706

2 Claims. (ci.y 292-258) Thisvinvention relates tosnap-on securingiclipsfor the lidsof sheet metal'v containers of'the type having av lever l'd seatedl in a ring secured tothe top of the side wall of the container bya seam overhanging said' side wallv out'- wardly thereof-sowas to form' in'eiect a' bead therearound', said lidl having the usual peripheral flange, curl, bead or the like by which it is levered oiff'to open'the' container, contiguous in the cross-section of the' lid with` the side wall of the depression therein" which is pushed'int'oY the seating ring whenJ the lid is in the" closed position therein.

y The object of the invention is'to provide' an' improved snap-on`- lid securing clip" for sheet metal containers of this type which will be marked by' a' high measure'of eliici'ency in use, coupledt with the characteristic that it' is easily"and' cheaply producibl'e-'in large quantities;

According" to' the invention, a snap-on' securing'clip'for the lido'f a sheet metal container of the'type above' referred to is characterised in that (a) ithas the shape in side elevation ofv a letter C whose curl at one en'd ofthe letter is prolonged tothe formof a straight tail' lying at an' angle substantially less ythan 90 to the lcenter portion of the C, the clip being thereby capable, after having been engaged at the end opposite the end at which the straight t-ail portion of the clip is situated under the overhangingseam at the top of the container wall, of being sprung over the inner edge of the'peripheral flange, curl, beadvor the like ofthe lid' (i. e. as regards vsaid tail portion) to a position in which thetail portion lies snugly against the sidewall of the depression in the 1id,-the said seam serving' in' this movement of the' clip as a fulcrum therefor, and'- (b') it is a' sheet steel stamping which has been bent to the shape specified and theny tempered'k to a desired degree of hardness to renderA permanentv the bent shape of the stamping and at the same time impart the necessary resilience thereto to enable it to be` sprung to `the position specified with a snap action. v

It is foundy that `a clipy of the foregoing description is easily and'cheaply ymanufactured in large quantities, parl ticularly if, according to a further feature of the invention,

the stampings which are firsty bent to the required shape and then tempered inthe manner set forth are stamped from a strip of steel of the required width of the clips, the

stamping operation Ibeing in this way considerably facili# tated and simplified as compared. with a case where the stampings are stampedl out of a blank in the form of a sheetr In addition, owing tothe fact that the stampings after having been bent to the required shape, said shape Abeing exactly the finished shape of the clip, are then tempered to a desired degree ofl hardness to render the bent shape of the stamping permanent and at the same time to impart to the stampingthenecessary resilience to ysnap action in theymanner hereinbefore set forth, the

clips of this invention exhibit a remarkable measure of enable it to be sprung to the lid securing position with a v y 2,743,128 Patented oAvpr. `24, 1,956kl v2I whilev on' the other hand" once they have been sprung to the' lid securing position they remain there permanently (i. e. until removed t'o release the li'd') however muchI the container may beknocke'dP aboutin the' course of handling; transportation'or'kstorage;

The latter mentioned characteristic of the clip, viz. its capacity to're'main in the lid securing position'gpermanently until removed' to release the' lid, is the more' pronounced if in accordance with aA further feature of theinvention, the clip is bifurca'ted'v at the curled endsofas to be'ofY a pronged formation thereat', the" pronged' formation prefer'- ably extending to' a p'ointne'ar the root ofthe tailportfon of the clip. f

The invention' will now be furtherdesc'ribed with reference to'l the accompanyingv drawings which illustrate' the invention by way'of example.

In'these drawings:

Figure l is' a vertical cross-section through the upper part' of a' container of the type he'reinbeforev referred t'o at one' side thereof and' through a clip in accordance with the'invention in the lid securing position;

Figure 2^ isla similar'se'ction showing the application of thev invention to"'a clip for use) wtha container in which thefdepressionY in the lid'as hereinbefore referred to is an annular depression' extending around: the lid" near the' periphery thereof' and' providing in kconjunction with a correspondingly'shaped'seating ringfor the lidth'e 'eiect of a d-ouble sealing joint" as between the lid andthe' container body, on'epart` of the joint' 'being at the radially inner side 'ofv the' annular. depression in the. lid and' the other at the radially outer' side thereof, the construction illustrated in Figure 1' being one inwhich the depression referred'- to is a dish shaped depression; v v

Figure 3' is a side elevationj of' the' clip appearing in section in Figure l; n

Figure' 4 isV a frontelevation of the' clip looking in the direction ofthe arrow I'V in Figure 3; v e

Figure' Sis a plan view'ofthfe clip looking in the direction ofthe arrow -V in F'g'ure3;

Figure y,6 is a' diagrammatic view illustrating the method by' Which'the clips' of the invention are producedl from a strip' of' steel ofy a' width corresponding' to'y the required width'of the clip's t'o Ibe produced;'and

Figures'7, 8', y9, 10, 11', 1'2 and 131 are views showing the' clip'in a' succession of stages of manufacture thereof from a strip'ofstee'l as referredV to in the description of Figure 6. 1 p p Like reference numerals" are appliedftolike parts-in the various'iigures;

Referring iirst to Figure l, the side wall of the container is markedI 1. Secured byv a so-c'alled/ double top seam Z'isa seating' ring-frl for the lidof the container.

The 'lidof th'e'container -isvo'fI lthe' usual dished formation, the. bottom' ofthe dish being, marked 4` 'and the sidewall thereof 5. p At thev top of the side wall 5 is the peripheral iiange 6 of the lid'by which the latter is 'levered olf to open the container and, as will lbe seen, said'side wall 5I seats against` a" skirtportion Tof the seating 'ring 3 extending inwardly of the' container in the customary manner, Ithe 'lid having a tightpushA-in Iit'rela'tivelyto `the seating ring.

The securing clip forming `the subject mattei'` ofthe invention has' theshape hereinbefore specified,` this shape being clearly illustrated in Figures 1', 3', 4 and 5 of the drawings. n

y rl'fhus, asv shown `in Figures -1y and 3, the shape of `the clip inthe side elevation thereof'is similar to that offa letter' C 'whose curl 8- 'at one end -of the letters `prolonged to 'then-form of a straight' tail 9'lying at anangle of substantially less than to `the centre portion 1-0 of th'eUCv. 'As clearly shown in Figures, 4 --and 5, the clip is bifurcated'at the curled end I1` thereof so as to be of a pronged formation lthereat, the pronged formation extending to a point 12 near the root of the tail portion 9 of the clip. The two prongs of the clip characteristic of said pronged formation are marked 13,114.

In applyingthe clip to secure the lid of the container, the latter having been pushed fully home to its closed position in the seating ring 3 of the container, the clip is first engaged at the curled end 11 of the clip under the double-top seam 2 (Figures l and 2) with the tip of Ithe tail portion 9 engaging the peripheral 4flange 6 of the lid at or near the root thereof, where the flange joinsl the side wall 5 of the depression in .the lid, this position of the clip being shown in chain line in Figure 1. The clip is then pressed by pressure (e. g. manual pressure) applied in the direction of the arrow A in Figure l to spring the tail portion 9 over the inner edge of the flange 6 of the lid to the position in which it appears in Figure 1, viz. a position in which it lies snugly and l'irmly against the inner sur-faceof the side wall 5 of the depression in the lid. During .this latter operation '1 the double top seam 2 functions as a fulcrum to the clip in the manner hereinbefore set forth, and as will be understood the clip assumes its final lid securing position with a snap action, the an-gle between the tail portion 9 of the clip and the centre portion 10 thereof being greater when the clip is iniits lid securing position and greater still during Ithe operation of springing 'the clip into said position past the inner edgey of the peripheral flange 6 of the lid, than it is in the clip in the rest (i. e. untensioned) condition thereof in which it appears in Figures 3, 4 and 5 of the drawings.

Referring to Figure 2, the annular depression hereinbefore referred to in the lid is marked and, as shown, the seating ring 3 is formed with a correspondingly shaped U-section flange portion 16. This portion 16 co-operates with the depression 15 to provide a double sealing joint as hereinbefore referred to in the description of Figure 2, and as will be seen, the lid in this construction of Figure 2` is provided with a peripheral curl 17 taking the place of the flange 6 of the lid of Figure 1, and although the clip which is generally marked 18 in Figure 2 is somewhat narrower along the center portion of the C than the clip of Figures l, 3, 4 and S, to accommodate the shorter distance between the curl 17 and the seam 2, as compared with the distance between the inner edge of the ange 6 and the seam 2 of the construction according to Figure l, the clip is otherwise of precisely the same construction as that of the Figures 1, 3, 4 and 5 and its method of application is the same as that of the clip of these other figures.

Referring now to the process of manufacture of the clip, this is illustrated in Figures 6 to 13 as herein-before indicated.

Figure 6 shows a supply reel 19 of untempered steel strip from which the clips of the invention are produced in a machine in which the strip is fed from the reel past a succession of operating stations marked 20, 21.

All of the operations which are performed upon the strip are performed automatically in the machine.

At station 20 a flat-diamond shaped aperture is stamped in the strip. Figure 7 shows a length of the strip having a succession of such apertures stamped in it, said apertures being marked 22 and the strip 23.

At station 21 a series of successive operations are performed, as follows:

(l) The strip is cut along two lines marked 24, 25 in Figure 7 so as to form a blank of the shape shownr in Figure 8. j

(2) The blank (Figure 8) is bent to the U form in which it appears in Figure 9, Figure 9 being a view of the blank edge on, i. e. looking in a direction parallel to the direction of width of the'blank. This operation and the preceding operation (l) are performed almost simultaneously and by one and the same tool assembly indicated diagrammatically in Figure 6 by the arrow 26,

which tool assembly co-operates with a stationary tool part 27 past which the strip 23 is fed in a succession of steps.

(3) The bent ends 28 of the stamping are further bent in the direction towards one another to the position in which they appear in Figure 10, i. e. to a position in which they are at an angle of substantially less than to the center portion 29 of the stamping. Usually this angle is in the neighbourhood of 70, although it may be any other necessary angle according to the shape and dimensions of the container and its lid with which the clip is to be used. This operation is performed by two further tool assemblies indicated diagrammatically in Figure 6 `by the arrows 30, 31, these tool assemblies 30, 31 operating simultaneously upon the stamping in respectively opposite directions and co-operating as in the case of the tool assembly 26 with lthe stationary tool part 27 of the machine.

(4) Immediately afterwards the outer extremities 32 of the bent ends 28 of the stamping are curled over to the form in which they appear in Figure 1l. Such curling over is produced by a fourth tool assembly indicated diagrammatically in' Figure 6 by the arrow 33, which also cooperates with the stationary tool part 27.

(5) The stamping is now slid down the stationary tool part 27 to a lowered position thereon.

(6) At this lowered position an hour-glass` shaped portion of the stamping, located at the centre of length thereof and shown in hatched lines in Figure l2, is stamped out of the stamping so as to part the latter into two identical halves, shown respectively at 34 and 35 in Figure 13. This operation is performed by two complementary cutting tools, one a female tool and the other a male tool, indicated in Figure 6 by the arrows 36 and 37.

(7) The parted stamping halves 34, 35 are now ejected from the machine.

Each of the said stamping halves 34, .35 is of the shape already described with reference to Figures 1, 3, 4 and 5 and it remains to perform the nal step in the manufacture of the clip, which consists in tempering the bent stamping to a desired degree of hardness to render permanent the bent shape of the stamping and at the same time impart the necessary resilience thereto to enable it to be sprung to the lid securing position in which it appears in Figure l, or as the case may be, Figure 2. Such tempering is performed by heat treatment of the bent stamping in an oven maintained at the requisite temperature.

What we claim as our invention and desire to secure by Letters Patent of the United States is:

l. A resilient spring steel snap-on clip for securing a dished lid to a container of the type having a top peripheral seam, said clip having a substantially straight main body portion, a crook-shaped portion at one end of said body portion, and a tail portion at the other end defining with said body portion an included angle of somewhat less than 90", said tail portion being cssentially flat from end-to-end, said crook-shaped portion and said straight main portion being bifurcated to a point adjacent the base of said tail portion, whereby when in operative securing position said crook-shaped portion contacts the side wall of the container immediately below said seam at at least two points and said tail portion projects downwardly within the lid and [its snugly against the inner surface of the side wall of the dished lid.

2. A resilient spring steel snap-on clip for securing to a container of the type having a top peripheral seam a lid having an upstanding generally cylindrical rim, said clip being generally C-shaped in side elevation with one end in the form of a straight tail which defines with the upright portion of the C an included angle of less than 90, the other end and said upright portion being notched to a point adjacent the base of the straight end,

whereby when in operative position said notched end contacts the side wall of the container immediately below said seam at at least two points, each of the two prongs defined by said notch being capable of independent movement relative to the other, and said straight end iits snugly against the inner surface of the cylindrical rim of the lid.

References Cited in the tile ofthis patent UNITED STATES PATENTS 374,715 Sullivan Dec. 13, 1887 6 Wilson June 15, 1915 Jesser Mar. 23, 1937 Judd Sept. 4, 1945 Sumner Apr. 3, 1951 Hansen July 8, 1952 Hanslick Feb. 24, 1953 FOREIGN PATENTS Great Britain July 24, 1894 Great Britain June 23, 1932 Great Britain Feb. 15, 1943 

